On Wed, Oct 05, 2011 at 10:26:54PM +0100, Chris Wilson wrote: > On Wed, 5 Oct 2011 13:01:56 -0700, Ben Widawsky <b...@bwidawsk.net> wrote: > > Docs say that the secure batchbuffer field for > SNB B0 (products that > > actually shipped) should be 0 when not using PPGTT. I'd guess this has > > no positive or negative effect, but is just here to jive with the docs. > > How explicit is the warning? Enough to allow arbitrary writes into the > MMIO space?
I've run this on my snb the past month and couldn't find anything this unbreaks. Afaics it allows batchbuffers to run a few more MI commands instead of hanging the gpu with them. But we're not using these from userspace and they only started to be allowed on snb+ - previous gens convert them to noops. Also this allows arbitrary reads/writes to system memory, because with this batchbuffers can update gtt ptes with MI_UPDATE_GTT. Even when we find an actual hang this fixes, I think implement ppgtt is the right thing to do. So NAKed-by: Daniel Vetter <daniel.vet...@ffwll.ch> -- Daniel Vetter Mail: dan...@ffwll.ch Mobile: +41 (0)79 365 57 48 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
